Damper-winding support



July 14, 1925.

c. c. BRINTON 1545'733 DAMPER WINDING SUPPORT Original Filed July 1, 1924 Patented July 14, 1925.

uNiTE-D .STAT-Es PATENT OFFICE.

CHARLESiC. BRINIOIST, OFEDGEWQOD, PENNSYLVANIA, ASSIGNOR TUWESTINGHOUSE ELECTRIC 8c MANUFACTURINGCOMPANY, A CORPORATION OF PENNSYLVANIA.

DAM-PER-'WINDING SUPPORT.

Application filed July 1, .1924,Seria1 T0 all who-m t may concern:

:Be it known that I, CHARLESG. BniNroN,`

a citizen of the VUnited Statesand a residentof Edgewood, lin `the countyof Allegheny r`and yState of Pennsylvania, have invented a .new and useful .Improvement in Damper-Vinding Supports, Y,of which the .following isa specification.

My invention relates to dynamo-electric machines and it has particular rrelation to a Vfield-pole construction for .supporting damper windings which are ,designed Vonly vfor use .in ymaking the machine self-starting and are, therefore, of .limitedv capacity.

,The object of :my invention is Vtoprov/ide novel features of construction which have -been 'found in ,practice Vto produce a highly meritorious `app aratus` avoiding manyV of the shortcomings of prior machines.

On polyphase synchronous machines, the ,damper winding is ordinarily designed-only for use in ,making the machine .self-starting and, therefore, is inservice for .only a v ery short time -during each starting operation.

For this ireason, the capacity of vthe Adamper winding is made very limited, providing little margin .for unusual conditions o'fI-,operation in which the damper winding maybe vcalled into-service. lhen abnormal' condi- -tions lcause Va burnout in the damper Awinding, -the failure usually occurs in .the imbeddedportion ofthe bar wherethere is no additional .fmaterial vto absorb the .heat geny erated ,-Furthermore, since this portionl of vthe .bar is unsupported, it will be destroyed lby the ycentrifugal Yforce .of rotation at a lower temperature than the imbedded and `supported portion. y

Furthermore, in the ,usual v.damper .construction,l it thas been necessary to employ `Vobtain yand require special shop lixturesfor {their manufacture.

A more. specific object of .my invention,

' .thereofore, is to provide a punched-lamination construction which shall 4replace the Vmalleable iron castings previously used. for lsupporting the ends of the damper bars and which shall be so designed as to provide the `necessary vheat storage capacity for preventing 'the end .parts .of .the damper 4bars from 4reaching ka dangerous temperature.

`XIV-ith fthe A'foregoing and other objectsin lview, my invention consists in- .the details .rand featuresof construction hereinafter de- No. 723,477. Renewed April 2, 1925.

scribed and claimed and illustrated in the acompanying drawing, wherein Figure l is an elevational view-of al portion of the salient-pole rotor member of a dynamo-electric machine provided with a damper winding in accordance with my invention,

Fig. l2 is a sectional view of a pole member illustrated in Fig. 1, taken along the line II-II thereof, and

Fig. 3 is a detail elevational view show- Vthe pole piece with the damper winding removed.

As shown in the accompanying drawing, my invention relates 'to ythe field ymember of a dynamo-electric machine which may comprise a central body member or yoke 1 to which are secured a plurality of pelar projections 2 comprising iron laininations 3 assembled and held vtogether by means of rivets 4 and mounted in the yoke 1 by means of dove-tail Iprojections 5 and corresponding dove-tail grooves 6 in the yoke.

"The tips of the polar projections 2 are built up laterally by means of additional 'lamina- .tions 7 and 8 lwhich are held in place by means of rivets 9 which extend throughout the entire lengtlhof the pole and the additional lamina-tions 7 y and 8 on both ends.

Field coils 11 are mounted upon the pole angle-sectioned copper segments 15, a seg- -malleable Iiron castings whichv are diilicult to portionof 'the pole pieces 2, in order to prevent the laminated extension?, 8 from providinga vmagnetic ,path which would direct some ofthe flux yinto V'the stationary parts (not shown) from ythe side instead of on 1 descrip-tion, that 'I have providedV a construction in which the damper bar is imbedded in the pole and in the built-up supporting extension, up to the point where it is attached to the. end ring. Thus, the `weak point of the damper winding, from the standpoint of heat capacity, is entirely j eliminated, and the ability of the winding to 'operate under abnormal and severe conditions is very greatly increased.

It is also obvious, from an inspection of my construction, that the damper winding is supported in a substantial manner well adapted to meet the growing demand for machines used in connection with hydro-` electric stations, since sucli machines must by means of the-.bolts and-the friction be-v operate at from 8O to 100 percent above V normal speed. My laminated extensionj, 8,

which is bolted to the main body of the pole aiece isretained against centrifugal force tween laminations, thereby amply support- 'ing the damper winding against rotational stresses.

' The material for making my new support, or laminated extension 7 8, is punched with dies built for other purposes from standard stock sheet material, which constitutes a de-` v cided` manufacturing advantage, as compared .with thev difficult casting Vnecessary in previous designs.V y VI claim as my'invention:

1. In an alternating-current synchronous machine, a field member having laminated polar projections, field windings thereon, the tips of said polar projections having lateral Vextensions built up of additional laminations, fastening means extending through the Vmainbody of said polar projections vand vsaid additional laminations for clamping the same together, the pole faces of said polar projections, including said latj Aeral extensions, being slotted, damping bars of limited capacity, Vsuitable for Vstarting duty only, disposed within'the slots, and

- short-circuiting means connecting the ends of said bars Vadj acentV said lateral extensions, the slotted laminations lof said lateral extensions furnishingthe bars with additional Y heat storage capacity necessary to prevent excessive local heating under abnormal operating conditions. Y Y

" 2. In an alternating-current synchronous machine, a rotatable field memberV having laminated polar projections, eld windings'v tips of said polar V.projections having lateral `means connecting the ends of said bars adjacent Vsaid lateral extensions, the slotted laminations of saidV lateral extensions furnishing the bars with additional mechanical support necessary to prevent ylocal buckling under abnormal "speed conditions.

'3. In an alternating-current synchronous machine, av field member having laminated polar projections, Afield windings' thereon, the

extensions built up of additional laminations, fastening means extending through the mainbody of said polar projections and said additional laminations for clamping the same together, the pole faces of said polar projections, including' said lateral extensions, being slotted, damping bars disposed within the slots, and short-circuiting Vmeans connecting the ends of said bars adjacent said lateral extensions.

4:. In an alternating-current synchronous machine, a iield member having laminated polar projections, field windings thereon, the tips of said polar projections having lateral extensions built up of additional laminations, a plurality of said additional laminations adjacent the main body portion of said polar projections being of non-magnetic material, fastening means'extending through the mainA body of said polar projections and the sametogether, the pole faces of Vsai polar projections, including said lateral extensions, being slotted'7 damping bai'sof lm-V ited capacity, suitable for starting duty only, disposed within the slots, and short-circuitving means connecting the ends of said bars adjacent said lateral extensions, the slotted laminations of Vsaid lateral extensions furnishing the bars with additional heat storlage capacity necessary to prevent excessive local heating underl abnormal operating conditions.V Y

5. In an alternating-current synchronous machine, a rotatable iield member having laminated polar projections, iield windings thereon, the tips of said polar projections having lateral extensions Abuilt up lofadditional laminations, a plurality of said additional laminations Vadjacent the main body portion ofjsaid polar projectionsfbeing of Vnon-magnetic material, fastening means extending through the main body of said polar projections and Ysaidadditional laminationsV for clampingV the saine together, the pole 1 said additional laminations for clamping nations adjacent the main body portion of said polar projections being of non-magnetic material, fastening means extending through the main body of said polar projections and said additional laininations for clamping the same together, the pole faces of said polar projections, including said lateral extensions, being slotted, damping bars disposed Within the slots, and short-circuiting means connecting the ends of said bars adj acent said lateral extensions.

In testimony whereof, I have hereunto subscribed my name this 30th day of June 1924.

CHARLES C. BRINTON. 

